Dosing mechanisms



March 14, 1967 FLANAGAN L 3,309,056

DOSING MECHANISMS Filed March 25, 1963 2 Sheets-Sheet 1 March I4, 1967 P. FLANAGAN ETAL 3,309,056

DOSING MECHANISMS Filed March 25, 1963 2 Sheets-Sheet 2 United States Patent O 3,309,056 DOSDIG MECHANISMS Peter Flanagan and Ronald Harvey David Frank Lee, Berlrhamsted, England, assignors to Cooper McDougall & Robertson Limited, Berkhamsted, England Filed Mar. 25, 1963, Ser. No. 267,648 Claims priority, application Great Britain, Mar. 30, 1962, 12,241/ 62 6 Claims. (Cl. 251-75) This invention relates to driven dosing mechanisms for actuating discharge valves fitted on pressure-packed containers to charge the ambient atmosphere at more or less regular intervals with a desired material in spray form. In this kind of mechanism a support is provided for positioning the container so that an operating arm of the mechanism will actuate the container discharge valve.

The container is charged, prior to use, with a composition comprising the desired material and a compressed or liquefied propellent. The composition is discharged under the pressure of the propellant and is in spray form because of the evaporation of propellant and the nature of a nozzle in the discharge valve button. The desired material in the composition is, for example, an insecticide, medicament or deodorant.

It has been found that both actuation and release of the discharge valve button should be abrupt. Manufacturing tolerances and continued use often cause the valve to operate not necessarily exactly as intended. In particular, the valve will not always close satisfactorily if the button is released slowly, and the inlet to a chamber in a metered valve, for the discharge of a predetermined amount of the composition in the container, will not in these circumstances always close completely before the outlet is opened. Further, the duration of discharge from a non-metered valve is determined by the duration of actuation of the valve button and rapid movement of the latter is important in alfording accurate control. The expression snap-action (as used hereinafter) is to be understood in this sense, requiring that the movement occurs during a very small period, preferably occupying no more than one second.

It is an object of the invention to provide simple means for effecting the snap release as well as the snap actuation of the discharge valve button of an aerosol dispenser. Another object is to provide such means in which the snap release and snap actuation are accomplished under the influence of the same biasing spring. Yet another object is to provide a dosing mechanism for actuating discharge valves fitted on aerosol containers, incorporating cam mechanism for releasing a spring-biassed valve-actuating arm in which the spring load on the cam mechanism is balanced.

The invention consists in a driven dosing mechanism of the kind referred to, comprising an operating arm for actuating a container discharge valve, a release arm for disengaging the operating arm from the discharge valve, and a cam mechanism embraced between said arms arranged to provide for sequential movement of said arms with a snap-action and with a predetermined interval therebetween. Preferably, the arms are spring-biassed towards one another thereby bearing in opposed directions against the cam mechanism.

Generally, the operating and release arms will be in the form of pivoted levers, which operate upon release by the cam mechanism. It is preferred that these levers are pivoted each to a fixed part of the dosing mechanism and are biassed by a common biassing spring which extends between the levers. Conveniently, the levers are pivoted together, at the same part of the dosing mechanism. By using a common biassing spring the spring load on the cam mechanism is balanced (except perhaps 3,399,956 Patented Mar. 14, 1967 momentarily Whilst one of the levers is describing a snap action). Also, it is preferred that there is a separate cam surface for each arm so that the latter are operated only once in each revolution of the cam mechanism. This provides for somewhat greater manufacturing tolerances in the cam mechanism and the respective followers. Of course, eVen when there are separate cam surfaces, it Will be realised that these may be defined around axially spaced parts of the same rotary cam mechanism which may be a moulding or a number of co-operating mouldings. A geared-down synchronous motor is normally employed to drive the cam mechanism.

It is preferred that the discharge valve fitted on the container is metered. It will be obvious that the time lapse between the operation of the operating and release arms is adjusted or predetermined to be greater than that required for discharge of the composition in the chamber of the valve.

The support for carrying the container may be such that the container stands directly on it or that the container is carried by a seam around its upper part. In the latter case, the support is, for example, in the form of a U-shaped recess into which the container is slid.

The parts of the dosing mechanism and the container may be of any acceptable material and shape. The operating arm, the release arm and the biassing spring may be of metal such as steel; and the cam mechanism and the button of the discharge valve may be of a plastic such as nylon, polythene or polyvinyl chloride. The container may be a tin-plated can with side-seams, or a glass bottle, or a can of impact-extruded aluminium.

The dosing mechanism has particular utility for containers in which the composition contains a deodorant. The ambient atmosphere can be deodorised at more or less regular intervals without any manual inconvenience. This is particularly valuable in public places such as restaurants.

An embodiment of the invention is illustrated in the accompanying drawings, in which:

FIGURE 1 is a front view of a dosing mechanism; and

FIGURE 2 is a side view of the dosing mechanism.

In FIGURE 1, the dosing mechanism is shown with a pressure-packed container 1 in position.

The container 1 is carried on a support 2 fitted on a lower portion of a casing 3 of box-like construction. A vertical plate 4 is fixed in the centre of the casing 3 and has a gap 5 for the container 1. Guides 6 on the support 2 ensure that a rectangular button 7 of a metered discharge valve fitted on the container 1 is in a position to be actuated by the dosing mechanism while the support plate 2 is inclined upwards slightly to ensure that the button rests against the plate 4. The valve also has an internal coiled spring (not shown) and is so positioned that a nozzle 8 in the button 7 points outwardly. A front cover 9 (shown only in FIGURE 2) is fitted onto the casing 3 and has an opening associated with a truncated conical shield 10 so positioned that the nozzle 9 is not covered.

On the back of plate 4 is a synchronous electric motor and gear box 11 from which extends a drive shaft 12 through the plate 4. The shaft 12 carries on the front of plate 4 a rotary cam mechanism having a spiral stepped cam surface 13, a separating plate 14 and a stepped circular cam surface 15 in that order outwardly; the steps on the cam surfaces 13 and 15 are fixed relative to each other at approximately One end portion of a hooked release arm 16 rests on the lower edge of the cam surface 13, and one end portion of an operating arm 17 on the upper edge of the cam surface 15. At their other end, the release arm 16 and the operating arm 17 are pivoted in that order outwardly on a shaft 18 fixed on the plate 4; there is a washer 19 between the par-ts on. the" shaft 18. The operating arm 17 carries an eccentric 20,

button 7.1 A milled-head screw 22 serves to clamp the eccentric 20 in a position where it will just clear, the buti ton 7 in the released position of the arm (as shown in chain-dotted outline in FIGURE 1). A biassing spring 23 stretches from the release arm 16 to the operating arm 17. There is a stop 24 at a central point on the release arm 16 for engaging and lifting the operating arm 17, and there is a stop 25 on the plate 4 for the release arm 16.

The cam mechanism is rotated in a clockwise direction by the synchronous electric motor and gearbox 11. The release'arm 16 is depressed against the tension of the biassing spring 213, and the operating arm 17 isfprirned. When the step in cam surface releases the end portion of the operating arm 17, the arm moves downwards abruptly. The-eccentric on the arm thereby actuates the button 7 by a snapacti0n.

The cam mechanism continues to rotate. vWhen the stepin cam surface 13 releasesthe end portion of the release arm-16,the arm moves upwards abruptly, and by its momentum carries the operating arm 17 with it upon engagement of the stop 24 with arm 17. The button 7 is thereby released by a snap-action, the internal coiled spring of the valve holding up the two arms 16 and 17.

If made of or cushioned with suitable material such as rubber, the stops 24 and 25 reduce the amount of noise when the dosing mechanism operates.

The cam mechanism will'continue to rotate and the" comprising an operating arm .for actuating the discharge valve, a pivotalmount for said. operating arm, a release arm'for disengaging the operating arm from the discharge valve, a pivotal mount for said release arm, cam mechanism embraced between said arms arranged to provide for sequentialmovement of the arms with a snap action and with a predetermined interval therebetween, means biasing each said arm about its pivotal mount'to bear against said cam mechanism, and meanson said release arm for striking said operating arm to displace said operating arm from its valve-actuating position.

2. Mechanism according to claim 1 in which eaoharm is spring biassed towards the other the arms thereby bearing in opposed directions against the cam mechanism.

3. Mechanism according to claim 2 in :which said arms are each in the form of levers pivoted to a fixed part of the dosing mechanism and which operate upon theirreleasebythe cam mechanism..

4. Mechanism according toclaim 3 in which the levers are biassed by a common .biassing spring which extends" between the levers.

5. Mechanismaccording toclaim 3 in which the. levers are pivoted together; at the same part of the dosing mechanism.

6. The mechanism as claimed in claim 1 in which said last-mentioned means constitutes a stop means carried by said release arm at a portion intermediate its ends and disposedto underlie said operating arm when the latter is in actuating position and to engage and abruptly lift said operating arm upon release thereof by said cam mechanism.

References Cited by the Examiner UNITED STATES PATENTS 2,800,773 6/1957 Crew 137-624.13 XR L. D. KA'MPSCHRQR, R'. 'C. MILLER,

' Assistant Examiners.

2/ 1961 Harris ZZZ- XR 

1. A DRIVEN DOSING MECHANISM FOR INTERMITTENTLY ACTUATING THE DISCHARGE VALVE OF A PRESSURE-PACKED CONTAINER, COMPRISING AN OPERATING ARM FOR ACTUATING THE DISCHARGE VALVE, A PIVOTAL MOUNT FOR SAID OPERATING ARM, A RELEASE ARM FOR DISENGAGING THE OPERATING ARM FROM THE DISCHARGE VALVE, A PIVOTAL MOUNT FOR SAID RELEASE ARM, CAM MECHANISM EMBRACED BETWEEN SAID ARMS ARRANGED TO PROVIDE FOR SEQUENTIAL MOVEMENT OF THE ARMS WITH A SNAP ACTION AND 